Direct butt welding of stainless steel and carbon steel pipes

Okay, thank you! But as the designer, it’s still necessary to pay attention to this. I was wondering if there are any ways to enhance strength; after all, when calculating the strength of stainless steel, no account is taken for corrosion allowance, while for carbon steel, 1.5 mm is taken into consideration. I hope for greater safety

This post was last edited by Simply put_myP89 on 2021-1-16 at 11:05. It is currently unknown what the operating status of the jacket is; without taking factors such as medium pressure into account, welding it directly is not recommended. There is no need to make design changes just because of construction considerations – this goes against the original intent of the design, and in fact, as a designer, you are failing in your duties! Let’s talk first about welding stainless steel and carbon steel. You probably haven’t considered carburization, which severely affects the corrosion resistance, ductility, and other mechanical properties of stainless steel, thereby creating significant safety hazards; this issue cannot be resolved simply by strengthening the material. Furthermore, if the structural design is altered without permission from the designer due to construction work. The designer has the right to refuse changes. From the perspective of protecting your own interests, it is recommended that you ask the contractor to provide a written report on the situation; you shouldn’t make changes just based on what the other party says. Your changes could even extend to affecting the responsibilities of those in charge of overseeing welding processes; in the event of an accident, how will you be able to take responsibility for it? The most common material substitutions, such as using thicker materials in place of thinner ones, require strict procedures. Moreover, when it comes to welding different types of steel, there are issues such as weld evaluation, selection of welding electrodes, welding processes, determination of the welding personnel involved, reduction in strength, potential risks of accidents, and physical and chemical tests on the materials – all of these are not things that a single designer can handle on their own. Pulling one thing affects the whole body. Finally, let’s talk about the awkward situation faced by designers these days. It is precisely because of your approach to work that construction delays affect the design process, forcing designers to follow orders blindly. This can be understood from an emotional perspective, but it should not occur in the work related to special equipment. Have the construction party conduct the impact test first. In reality, in the situations I’ve been involved in, there was once an organization where something similar to what you described happened, and as a result, the equipment exploded. Designing is difficult, but the principles cannot be changed. If you change it once, you’ll need to change it everywhere else – that’s inertia. Your compromise could indirectly turn into a killer. Serious, strict, meticulous, and disciplined.

I understand the logic – wait until I change jobs

You’re great at changing jobs… I suggest waiting until after the pandemic before considering changing jobs. It’s better to look for a horse while riding a donkey.

The outer jacket tube is directly welded to the existing 304 pipe; welding of such dissimilar steels can lead to accelerated corrosion, which may result in corrosion-induced leaks quite quickly.